Clean up parameterized typedefs

Express them in terms PolyTypeTrees rather than having an
irregular, untyped only tparams field. This is necessary
if we want to pickle type trees instead of types, because
now the rhs of a typedef tells the whole story, so we are not
required any longer to use the info of the symbol.

2 files changed, 6 insertions, 7 deletions

diff --git a/src/dotty/tools/dotc/core/tasty/TreePickler.scala b/src/dotty/tools/dotc/core/tasty/TreePickler.scala
index 9dfb78798..98a369f25 100644
--- a/src/dotty/tools/dotc/core/tasty/TreePickler.scala
+++ b/src/dotty/tools/dotc/core/tasty/TreePickler.scala
@@ -49,10 +49,6 @@ class TreePickler(pickler: TastyPickler) {
       case None =>
     }
   }
-  
-  def rhs(tdef: TypeDef)(implicit ctx: Context) = 
-    if (tdef.symbol.isClass) tdef.rhs
-    else TypeTree(tdef.symbol.info).withPos(tdef.rhs.pos)
 
   private def pickleName(name: Name): Unit = writeNat(nameIndex(name).index)
   private def pickleName(name: TastyName): Unit = writeNat(nameIndex(name).index)
@@ -336,7 +332,7 @@ class TreePickler(pickler: TastyPickler) {
     tree match {
       case tree: ValDef => pickleDef(PARAM, tree.symbol, tree.tpt)
       case tree: DefDef => pickleDef(PARAM, tree.symbol, tree.tpt, tree.rhs)
-      case tree: TypeDef => pickleDef(TYPEPARAM, tree.symbol, rhs(tree))
+      case tree: TypeDef => pickleDef(TYPEPARAM, tree.symbol, tree.rhs)
     }
   }
 
@@ -478,7 +474,7 @@ class TreePickler(pickler: TastyPickler) {
         }
         pickleDef(DEFDEF, tree.symbol, tree.tpt, tree.rhs, pickleAllParams)
       case tree: TypeDef =>
-        pickleDef(TYPEDEF, tree.symbol, rhs(tree))
+        pickleDef(TYPEDEF, tree.symbol, tree.rhs)
       case tree: Template =>
         registerDef(tree.symbol)
         writeByte(TEMPLATE)
diff --git a/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala b/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
index d2605afea..90f718402 100644
--- a/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
+++ b/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
@@ -696,7 +696,10 @@ class TreeUnpickler(reader: TastyReader, tastyName: TastyName.Table, posUnpickle
             TypeDef(readTemplate(localCtx))
           } else {
             val rhs = readTpt()
-            sym.info = rhs.tpe
+            sym.info = rhs.tpe match {
+              case _: TypeBounds | _: ClassInfo => rhs.tpe
+              case _ => TypeAlias(rhs.tpe, sym.variance)
+            }
             TypeDef(rhs)
           }
         case PARAM =>